1. Field of the Invention
This invention relates to a shielded cable-grounding structure for grounding a braided wire at an end of a shielded cable.
2. Related Art
There is known one conventional shielded cable-grounding structure in which one side portion, extending from a shielding terminal, is placed on an insulating sheath, and a resin chip is laid on the one side portion extending from the shielding terminal, and in this condition ultrasonic vibration is applied to fuse and dissipate at least the relevant portion of the insulating sheath, thereby forming a shielding conducting portion at which the one side portion, extending from the shielding terminal, is electrically connected to a braided wire of the shielded cable (see, for example, JP-A-11-135167).
There is known another conventional shielded cable-grounding structure in which a shielding layer of a shielded cable is turned back on an outer periphery of an insulating sheath at an end portion of the shielded cable, and the turned-back shielding layer and the insulating sheath are press-fastened by a barrel of a metallic shell in such a manner that claws of the barrel extend through the shielding layer, and bite into the insulating sheath (see, for example, JP-A-10-270123).
In the above JP-A-11-135167, however, an end portion of a lead wire is placed on the insulating sheath, and the resin chip is laid on this end portion, and in this condition the shielded cable, together with the lead wire end portion and the resin chip, is held between a pair of ultrasonic horns, and ultrasonic vibration is applied to this portion while applying a pressure from the upper side of the resin chip. Therefore, there is a fear that a large load is applied to the braided wire and a core portion to damage them.
In the above JP-A-10-270123, the claws of the barrel are brought into biting engagement with the shielding layer, and therefore there is a fear that the shielding layer is damaged.
Usually, it is desired that a braided wire of such a shielded cable is woven into a mesh-like structure, and covers an entire periphery of a signal conductor over an entire length thereof so as to form a positive grounding circuit so that disturbance noises will not reach the signal conductor.
In a conventional shielded cable-grounding structure shown in FIG. 7, however, a sheath 51 is peeled and removed from an end portion of a shielded cable 50, and an end portion of a conductor 53 is exposed by separating a braided wire 52 therefrom, and a distal end portion of the conductor 53 is peeled, and is press-connected to a terminal 54. The braided wire 52, separated from the conductor 53, is twisted, and a tape is wound on the twisted braided wire 52, or a shrinkable tube is fitted on the twisted braided wire 52, and a distal end portion of the braided wire 52 is cut off for trimming purposes, and the trimmed end portion of the braided wire 52 is press-connected to a terminal 55. Therefore, the efficiency of the operation is low, and besides since the exposed braided wire 52 is twisted to assume a generally linear configuration, a disturbance-intercepting capacity is reduced, so that there is a fear that the effect of shielding the exposed conductor 53 is lowered. On the other hand, the exposed conductor 53 (which is separated from the braided wire 52, and extends to the terminal 54), has a non-shielded portion or region which is not covered with the braided wire 52, and is to be received within a connector. Furthermore, much time and labor have been required for the additional operations (including the operation for trimming the distal end) for the braided wire 52.